I have a 2015 MINI Cooper hardtop, which introduced me to the coding (should be called changing parameters to be more precise). Basically you use ESYS to change some values and write that in your 10 or so ECUs. You can change things like getting rid of the annoying “do you agree?” disclaimer prompts in the start of your car, change some behaviors like auto engine on/off, climate control AC auto on/off, LED bulb check, etc. There’s also a program called Reingold which has a bunch of tear down and service instructions meant for the service department. Is there such a thing on Honda Clarity?
You can get access to Honda service information online. There are folks on here who have accessed it. I think you pay by the day/week/month, etc. There is a program called HondaHack that will allow you to customize some of the disclaimer and other features. You can also use it to reprogram the steering wheel audio controls to function differently than they do as stock.
